Technical Abstract:
Loaf volume (LV) is the principal component of bread quality evaluation of breeding lines and rapeseed displacement has been the method of choice for over 60 years at the HWWQL. A new computer-controlled LV measuring instrument, which employs laser sensor (LS), has become commercially available. The objective of our study was to investigate the potential use of the LS instrument for measuring LV of pup-straight-dough-bread (PUP: 100-g flour) and pound-sponge-&-dough-bread (POUND: 300-g flour). Using 43 flour samples (19 hard winter and 24 hard red spring wheat) from the Wheat Quality Council test samples, harvested in 2004, the LV values by rapeseed were generally higher than those by LS instrument. The overall average values of LV by rapeseed were 847 and 2256 cc for PUP and POUND, whereas those by LS were 700 and 2010 cc, respectively. The differences in LV values obtained between the two methods depend on the LV values of samples, i.e., a larger difference for a larger loaf of bread, especially for the PUP (R-square=0.673) and to lesser degree for the POUND (R-square=0.154, P<0.01). The LV values were highly correlated between the two methods, irrespective of wheat classes, baking methods (straight-dough vs. sponge & dough) or sample size (100- or 300-g flour). The correlations between the two methods were highest for winter wheat of PUP and POUND (R-square=0.997) and lowest for spring wheat PUP (R-square=0.840). With all 86 data, R-square value was 0.996. Rapeseed LV values could be predicted significantly (R-square=0.993) using the LS instrument values such as LV, width, max depth, and area. Therefore, this new LS instrument has a potential to be used as an objective measurement instrument of LV for various bread products.